A conventional stacking apparatus 10 is illustrated in FIG. 1. The stacking apparatus 10 is configured for use adjacent to a rotary die cut machine 12 which cuts blanks (not illustrated) from sheets of material, for example, corrugated paperboard. The stacking apparatus 10 includes a receiving or “layboy” section 14 (sometimes referred to herein as a “layboy conveyor”) that receives the blanks from the die cut machine 12 and discharges them onto a transfer conveyor 16. The transfer conveyor 16 carries the blanks to an inclined main conveyor 18 along which the blanks travel and from which they are dropped to form a stack. The disclosure is directed to an improved layboy section of a stacker, and this layboy section can be used as the layboy section of any conventional stacker design. Further details regarding stackers can be found in U.S. Pat. No. 7,753,357 assigned to A.G. Stacker Inc., the entire contents of which is hereby incorporated by reference.
A conventional die cut machine is provided with webs or sheets of material from which blanks having a desired shape are cut. Die cut machines produce a certain amount of scrap material during operation which consists mainly of the portions of the input material that do not become part of a finished blank. In addition, each blank may include slots or through-openings. The material cut from the blank to form these slots and through-openings also constitutes scrap.
Most scrap material produced by the die cut machine drops beneath or immediately in front of the die cut machine as it operates. However, scrap material, especially small, lightweight pieces of scrap material, may be ejected from the die cut machine in such a manner that it falls into the layboy section from above or is drawn into the intake end of the layboy section either alone or along with the blanks Excessive scrap in the transport path between the layboy section and the final stack of blanks may adversely affect the transport of the blanks That is, the scrap may interfere with the alignment of the blanks or lead to jams. Alternately, if the scrap is carried all the way through the stacker and into the final stack of blanks, the blanks in the stack will have gaps therebetween where the scrap material is present thus resulting in a crooked, or oversized or non-uniform stack of blanks It would therefore be desirable to provide an apparatus and method for reducing the amount of scrap material from a die cut machine that enters the layboy section of a stacker.